The present invention relates to medical x-ray systems and, more particularly, to a system for producing uniform x-ray film images from electronic images.
Currently available film writing systems are subject to variations in their light output which give rise to variations in film density. Such film density variations may effect the ability to accurately diagnose medical problems using x-ray film analysis. The problems of film density variation are also aggravated by variations in the film itself and in the film processing. Since film processing involves a chemical treatment and reaction, the chemicals become contaminated with repeated use resulting in film density variations as a function of time and use.
Compensation for film density variations in the currently available processing systems have relied on trial and error techniques. Typically, a known reference image signal is provided to the system and a film exposed and developed. An operator then evaluates the image density on the film and adjusts the gain of the system in a direction to compensate for any deviations in film density from a desired norm. This process is repeated until a satisfactory film density is attained. Unfortunately, instabilities in the control system for the light source and changes in the film processing result in early deterioration of film quality thus requiring a repeated alignment procedure by trial and error adjustment.
It is an object of the present invention to provide an improved system for converting electronic images to film images.
It is another object of the present invention to provide an improved system for converting electronic images to film images which automatically compensates for variations in light output.
It is a further object of the present invention to provide an improved system for converting electronic images to film images which includes compensation for variations in film density.